AHSG and obesity due to melanocortin 4 receptor deficiency: Besides, epidemiological investigations also showed that fetuin-A and fetuin-B not only played a role in the development of obesity, hyperglycemia, and hypertriglyceridemia, but also led to chronic diseases, such as metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) [3,4].